Transformer for alternating-cur-rent systems



l(No Model.) 'l

4JL. THoMsQ-N. n TRANSPORMER FOR ALTEBNATING CURRENT SYSTEMS.

No. 542,295.. llmmninaa July D; '1895.

UNITEDA STATES ELmU THOMSON, or swruurscoTT, MASSA eHUsET'r-s, AssIGNoR To 'rnE GENERAL ELECTRIC COMPANY, N-EV YORK. 7

TRANSFORMER Fon AtTinrfiATiNgs-cu RRENT SYSTEMS.-

SPECIFICATION 'forming part of Ict/ters-Tatent No. 542,295, dated July 9, 1895i rppiiatii nga umn 6,/1895. sean Na 540,699.. (Nu maar.)

the other.

zen of the UnitedStatearesidingat Swamp- Iscottin the countyot Essex,S tate of Massal'eh usetts,have in vented certain newand useful Improvements in Transformers for Alternat. Y

ing-Current Systemsyofwhieh the following is a specification.

lily invention 'relates to transformers for alternatingcurrent systems; and it has for its object to provide a safety ground connecf tion for such transformers, aording a. wayof separating two lines-whilestill keeping them in inductive relation. It is particularly applieable to cases where there is danger from lightning or where high potentials are employed.

My invention consists, substantially,of a double transformer with coils upon each core and links or plates of copper extending through and forming a primary winding on one transformer and a secondary windingon These plates'or sheets are practica'llyat no potential,and are therefore connecled directly to ground and ,serve as an efficient safety connection in case of leakage from any coilof the transformer to the plates or sheets, thereby avoiding the possibility of leakage through the winding.

The accompanying drawings show embodimentsfof my invention, Figure l being a plan, Fig. 2 a side elevation, and Fig. 3 a detail,of one of the links, the earth connection being indicated diagrammatically. l

A l; arc the cores of the double transformer, which are, as usual, niade of laminated metal.

l is the primaryeoil connected to anysource of alternating current.

C C are the interposed links or plates of copper threaded between the coils,whieh are made sectional for this purpose and embracin;r both coils of the transformer.

'lho coils S upon the core ll of the transformer are the sectional coils and may be arranged, as shown, in series or in multiple, as

"l usi red.

An earth connection E is'inade to the links vmary andv secondary coils, the

In many cases immunityfrom vleakage be- 5o tween'the circuits or from the transformer to ground' may be imperative; and in such cases I have found that the ordinary copper sheet separating the coi.ls,- although sufficient in ordinary circumstances, is not sufiicient if the currents are'very heav as in that case the sheet must be made of very-thick metal and gets veryhot, and if its temperature rises verymuch by arcinglit becomes inefficient 'forthe purposes designed; The arrangement herein pointed ,orut is also desirable where the .circuit `is to bedivided into two parts, as when it-wonld otherwise be of very nrreat length or where one sectionjis subject to lightning eieet and the other section-not so subject. It also serves as an absolute protection to the generator or motoryvhen used as a step-up or step-down transformer. "It is also useful in vdiminishing capacity effects in the line and as furnishing self-induction to balance the capacity. j

That I claim as new, and desire to secure by Letters Patent of the United States, is'

- 1. A transforinerfor alternating currents, comprising two laminated co res, primary coils -wound upon one'of the cores, secondary coils upon theother, and plates or links ofcopper connecting the cores and adjacent to the priplates being connected to earth.

2. A transformer for alternating currents, comprising two laminated cores, primary coils ,wound upon one of such cores,secondarycoils wound upon the other,and connecting plates or links of copper interposed between the sections of the primaryand secnndarycoils,each plate'or link being 'intel-.posed -between coils of both types, and all the plates being connected to earth.

In witness whereof I have hereunto set niy hand this 28th dayof Februar-531895.

Ennio' 'rnoMsoNl 

